吗啉取代萘并吡喃化合物的结构性能关系研究

Structure-function Relationship Study of Morpholine Substituted Naphthopyran Compound

采用氯气氧化萘酚,使其形成α,β-不饱和酮,通过亲核加成引入吗啉取代基,再Pd-C催化加氢除氯恢复萘环,得到含吗啉取代基的萘酚,进一步与炔醇反应,即得到6-位吗啉基取代的萘并吡喃化合物(NP-6MP),结构经核磁共振和质谱进行确证。采用Hyperchem程序包中的半经验AM1程序,对产物的闭环体和开环体的结构性能关系作了研究。闭环体中,萘并吡喃环保持了较好的平面性,与螺碳原子相连的2个苯环被相互排斥在环平面两侧,保持闭环体为无色状态,分子堆砌较为疏松;吡喃环中O(1)-C(3)的键长1.455长于O(1)与萘环相连的键长1.378,表明O(1)-C(萘)更接近于双键,而O(1)-C(3)更接近于单键,因此光致结构互变时化学键的断裂点就是O(1)-C(3);O(1)-C(1)-C(2)的键角为113.02°,张力较大,有利于光致结构互变。开环体以全反式醌式构型作为几何构型优化的起点,二烯部分与萘环并不充分共面,这是受一个烯氢与萘环氢的排斥作用影响,分子轨道波函数(HOMO)的计算也证实了整个开环体是个弱的大π共轭体系。使得该化合物并没有产生预期的明显的吸收光谱红移。

The morpholine substituted naphthopyran compound （NP-6MP） was prepared via chlorine oxidation, morpholine substitution, Pd-C catalyzed hydrogen reduction and the cyclization with 1,1-diaryprop-2-yn-1-ol. Its structure was characterized by NMR and MS methods. The structure-function relationship of the closed and open form of the compound was studied by the AM1 method in the Hyperchem package. In the closed form, the backbone of the naphthopyran kept its planarity and two benzene rings were repelled to the two sides by each other. In the pyran ring, the bond length of O（1）-C（3） of 1. 455A was longer than that of O（1）-C（naphtho） （1. 378A）, which indicated that the O（1）-C（3） was considered as a single bond rather than a double bond. The angle of O（1）-C（1）-C（2） was as small as 113. 02° and indicated a strong tension which might be beneficial to the photochromism. In the open form, the all-trans quinone form was proposed as the start configuration for geometric optimism. The merocyanine part could not keep good planarity with naphtho ring, which was due to the repelling force from the hydrogen of naphtho ring. A weak n conjugation was observed throughout the backbone in the open form of the molecule by simulation of the wave function （HOMO）.